Switching devices, as key nodes in a network, are monopolized by existing device vendors, so that open interfaces of the switching devices are very limited, and many open ideas and protocols about the network cannot be tested and verified. The OpenFlow, as a set of switching standards having open interfaces and supporting multiple control, comes into being. The OpenFlow reconstructs, to a dynamic and changeable software defined network (SDN), conventional hardware that is physically fixed, which implements separation between a control plane and a forwarding plane. An OpenFlow switch (Switch) includes a flow table (Flow Table), a secure channel (Secure Channel), and an OpenFlow Protocol (OF Protocol). The flow table stores core information, so as to implement functions, such as searching, forwarding, collecting statistics, and filtering. The flow table includes multiple flow entries (Flow entry), one flow entry corresponds to one forwarding rule, and for a packet entering a switch, a destination port for forwarding is obtained by searching the flow table. The OpenFlow switch is connected to an external controller (Controller) through a secure channel (Secure Channel) by using the OpenFlow Protocol, and the controller searches and manages the flow table.
An SDN architecture is introduced to a next generation packet core network (SAE), so as to separate a function of a control plane of a gateway from a function of a forwarding plane of the gateway. The control plane of the gateway installs a flow table corresponding to an attached user onto the forwarding plane of the gateway, so as to implement forwarding of a data packet. A process of setting up a bearer for the attached user is as follows: an MME sends a create session request message to the control plane of the gateway; the control plane of the gateway encapsulates a user profile, such as a tunnel end point identifier (TEID for short) of a user, that is in a create session request, into a flow table and sends the flow table to the forwarding plane of the gateway; the forwarding plane of the gateway returns a flow table installation response message to the control plane of the gateway, and subsequently forwards a packet according to the flow table; and after receiving the flow table installation response message, the control plane of the gateway feeds back a create session response message to the MME, which indicates that the flow table is successfully created.
It may be seen from the foregoing process that, each time when a bearer of an attached user is generated, a flow entry is established on the forwarding plane of the gateway, which causes that a quantity of flow entries on the forwarding plane of the gateway is directly proportional to a quantity of attached users. However, the quantity of flow entries supported by the forwarding plane of a current gateway is relatively small currently, and there is an order of magnitude of difference between the quantity of flow entries and demands of a current user. In addition, a large quantity of flow entries is not beneficial for implementation of hardware of the forwarding plane, which causes deterioration of performance of the forwarding plane.